This invention relates to a cover for a container, such as an aerosol container, for preventing dust and other contaminants from contacting the dispensing mechanisms and possibly the contents of the container. More particularly the invention relates to a tamper-evidencing cover which may be removed initially only by breaking a seal to evidence the fact of such initial removal.
Tamper evident covers have come into wide use especially for food products and the like to assure ultimate purchasers that the contents and product-dispensing parts of the container have remained inviolate and free of contamination after the filling of the container by the manufacturer. There have been many proposals for such tamper evident covers. One of these is disclosed in my application Ser. No. 017,862 filed Feb. 24, 1987, now U.S. Pat. No. 4,744,483, which features a separate frangible ring shaped to encircle the base of the cover for maintaining the inwardly extending flange of the base in its locking position under the head of the container top closure. While the design is an excellent one, it is costly to produce.
Other prior art devices have included pull-tabs in the sidewall of the cover with a gripping member requiring the pull-tab to be removed by pulling downwardly. The problem with such a design is that it is difficult to start tearing of the pull-tab with a pulling action and the frangible lines thus have to be so thin in such a design that they result in discontinuities. Thus they do not tightly seal the top of the container.
The present invention provides a tamper evident cover which is completely imperforate throughout its structure providing a tight seal for the container top. The cover is inexpensive to produce and may easily be torn frangible lines which may be clearly seen and which will permit the cover to be easily removed from the container. The design provides a leveraged initial tearing along the frangible lines of the pull-tab and the initial tearing may be accomplished by pushing up or pulling on the pull-tab.